Apparatus and methods for removing material from a body lumen

ABSTRACT

Devices, methods, and kits for removing material from a body lumen. The devices and methods may be used in a variety of body lumens, including but not limited to coronary arteries and other blood vessels. In general, the device or catheter has a scoop-shaped cutting blade mounted on a catheter body for removing material from a body lumen. The cutting blade has a cutting edge that travels a curved path about a pivot point of the blade, preferably moving in an outward direction from the catheter body to engage the target material for removal. The scoop-shaped blade has a collection surface located behind the cutting edge to collect material removed from said body lumen. Advantageously, a scoop-shaped cutting blade according to the present invention facilitates material engagement and the collection surface may be used to bring material back into the catheter body as the blade begins to part-off material. The cutting blade is usually mounted to move in an inward direction towards the catheter body after the cutting edge has engaged the material. The cutting blade can also more easily engage occlusive material that is compressed against the body lumen wall.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a continuation of, and claims the benefit ofpriority from U.S. application Ser. No. 09/377,894, filed on Aug. 19,1999, the full disclosure of which is incorporated herein by reference.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH OR DEVELOPMENT

[0002] Not Applicable

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAMLISTING APPENDIX SUBMITTED ON A COMPACT DISK.

[0003] Not Applicable

BACKGROUND OF THE INVENTION

[0004] The present invention relates generally to apparatus and methodsfor removing occluding materials from body lumens. More particularly,the present invention relates to the construction and use of atherectomycatheters for excising atheroma and other materials from blood vessels.

[0005] Cardiovascular disease frequently arises from the accumulation ofatheromatous material on the inner walls of vascular lumens,particularly arterial lumens of the coronary and other vasculature,resulting in a condition known as atherosclerosis. Atherosclerosisoccurs naturally as a result of aging, but may also be aggravated byfactors such as diet, hypertension, heredity, vascular injury, and thelike. Atheromatous and other vascular deposits restrict blood flow andcan cause ischemia which, in acute cases, can result in myocardialinfarction. Atheromatous deposits can have widely varying properties,with some deposits being relatively soft and others being fibrous and/orcalcified. In the latter case, the deposits are frequently referred toas plaque.

[0006] Atherosclerosis can be treated in a variety of ways, includingdrugs, bypass surgery, and a variety of catheter-based approaches whichrely on intravascular widening or removal of the atheromatous or othermaterial occluding a blood vessel. Of particular interest to the presentinvention, a variety of methods for cutting or dislodging material andremoving such material from the blood vessel have been proposed,generally being referred to as atherectomy procedures. Atherectomycatheters intended to excise material from the blood vessel lumengenerally employ a rotatable and/or axially translatable cutting bladewhich can be advanced into or past the occlusive material in order tocut and separate such material from the blood vessel lumen. Inparticular, side-cutting atherectomy catheters generally employ ahousing having an aperture on one side, a blade which is rotated ortranslated by the aperture, and a balloon or other deflecting structureto urge the aperture against the material to be removed.

[0007] Although atherectomy catheters have proven to be successful intreating many types of atherosclerosis, known catheter designs may beimproved to further enhanced performance. For example, many knownside-cutting atherectomy catheters have difficulty in capturingoccluding material in the cutting aperture. Conventional atherectomycatheters typically use cutters mounted within openings on the sidewallof the catheter body. Some of these conventional catheters are difficultto position in the body lumen to engage the target tissue or materialwith these sidewall openings since the catheter must typically bepositioned so that material will intrude into the opening. This may makeit difficult to remove certain types of obstructions which do not lendthemselves to being received in the catheter aperture. Furthermore,catheters which require material to intrude into the catheter aperturelimit the aggressiveness with which materials can be removed in severeocclusion type blockages. Additionally, it is often difficult forconventional atherectomy cutters to apply the requisite pressure to cutoff the targeted tissue or material. This decreases the effectiveness ofthese cutters and limits the cutter and catheter designs.

[0008] For these reasons, it is desired to provide atherectomy catheterswhich can access small, tortuous regions of the vasculature and whichcan remove atheromatous and other occluding materials from within bloodvessels in a controlled fashion with minimum risk of injuring the bloodvessel wall. In particular, it is desired to provide atherectomycatheters which can facilitate capturing and parting-off of occlusivematerial. It would also be particularly desirable to have catheterswhich can remove occlusive material located near the catheter but do notintrude into the catheter aperture. At least some of these objectiveswill be met by the catheter and method of the present inventiondescribed hereinafter and in the claims.

BRIEF SUMMARY OF THE INVENTION

[0009] The present invention provides devices, methods, and kits forremoving material from a body lumen. The catheters and methods of thepresent invention may be used in a variety of body lumens, including butnot limited to coronary arteries and other blood vessels. In general, acatheter of the present invention has a scoop-shaped cutting blademounted on a catheter body for removing material from a body lumen. Thecutting blade has a cutting edge that travels a curved path about apivot point of the blade, preferably moving in an outward direction fromthe catheter body to engage the target material for removal. Thescoop-shaped blade has a collection surface located behind the cuttingedge to collect material removed from said body lumen. Advantageously, ascoop-shaped cutting blade according to the present inventionfacilitates material engagement, and the collection surface may be usedto bring material back into the catheter body as the blade begins topart-off material. The cutting blade is usually mounted to move in aninward direction towards the catheter body after the cutting edge hasengaged the material. The scoop-shaped cutting blade can also moreeasily engage occlusive material that is compressed against the bodylumen wall since the blade may be mounted to extend outward from thecatheter body.

[0010] Desirably, the blade or blades of the catheter will be actuablewith the application of reasonable mechanical forces which are capableof being transmitted along even rather lengthy catheters. Furtherdesirably, the catheters will be suitable for directional removal ofoccluding material and will include mechanisms for engaging cuttingblades against selected portions of a vascular wall. Optionally, thecatheter should permit blood perfusion during performance of anatherectomy procedure. Preferably, but not necessarily, the cutting edgeof the cutting blade will extend outside of the catheter body to engagematerial in a body lumen. Typically, the cutting blade rotates to placethe cutting edge in the desired position. The arc defined by therotation of the cutting blade is usually large enough to place thecutting edge outside the boundaries of the catheter body. The aperturefrom which the cutting blade extends may be located at a variety ofpositions on the catheter body, such as along the sidewall of thecatheter or at the distal end of the catheter body. Devices having thecutting blade located at the distal end of the catheter may be used tobore through material in a substantially occluded body lumen.Preferably, the cutting blade has a mating surface on the catheter bodyto assist in the parting-off or cutting of material.

[0011] According to the present invention, embodiments of the cathetermay have a scoop-shaped cutting blade that reciprocates longitudinallyalong a guide, such as a slotted track, a rail, or a ramp, to a positionoutside the catheter body. Furthermore, the cutting blade may be rotatedabout its pivot point while the blade is reciprocated longitudinally. Acutting blade that travels longitudinally while rotating about its pivotpoint can simulate the movement of a surgical curette/bone scrapingdevice to remove greater amounts of material from the body lumen.Advantageously, such a rotating and translating motion may allow thecatheter to lie stationary in the body lumen while the cutting bladetravels out from the catheter body to grab material and return towardsthe catheter body to part it off. Rotation and translation also allowsmaterial to be removed and collected in a simultaneous manner. Rotationof the cutting blade may also increase the amount of force that may beapplied against the material (since both translational and rotationalforce may be applied). The cutting blades used on the present inventionmay also include needles or other sharpened points to penetrate into thematerial to grasp the material before it is parted off.

[0012] In another aspect of the present invention, a method is providedfor excising occlusive material from within a body lumen. The methodcomprises positioning a catheter body having a scoop-shaped cuttingblade adjacent to a target material in the body lumen. Material may beparted off from the body lumen by rotating the cutting blade about apivot point to engage and cut the target material while urging thematerial into the catheter body with a material collection surface onthe cutting blade. Of course, in some embodiments, the cutting blade maytranslate longitudinally while being rotated about a pivot point of thecutting blade. The longitudinal moving step usually involvesreciprocating the cutting blade between a first position where thecutting edge is outside the catheter body and a second position wherethe cutting edge is substantially within the catheter body.

[0013] In a still further aspect, kits according to the presentinvention will comprise a catheter having a material capture device. Thekits will further include instructions for use setting forth a method asdescribed above. Optionally, the kits will further include packagingsuitable for containing the catheter and the instructions for use.Exemplary containers include pouches, trays, boxes, tubes, and the like.The instructions for use may be provided on a separate sheet of paper orother medium. Optionally, the instructions may be printed in whole or inpart on the packaging. Usually, at least the catheter will be providedin a sterilized condition. Other kit components, such as a guidewire,may also be included. A further understanding of the nature andadvantages of the invention will become apparent by reference to theremaining portions of the specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a perspective view of an atherectomy catheterconstructed in accordance with the principles of the present invention.

[0015] FIGS. 2-4 show cross-sectional views of a cutting blade accordingto the present invention mounted in the catheter of FIG. 1.

[0016] FIGS. 5-8 show various views a cutting blade according to thepresent invention mounted at the distal end of the catheter.

[0017] FIGS. 9-10 are cross-sectional views of a cutting blade which mayrotate and translate longitudinally along the catheter.

[0018] FIGS. 11-13 depict further embodiments of a cutting bladeaccording to the present invention which move along a longitudinal path.

[0019] FIGS. 14-17 show a cutting blade of FIG. 9 used to removematerial from a body lumen.

[0020]FIG. 18 shows a kit according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention provides devices, methods, and kits for usein removing material from a body lumen. The present invention may beused in a variety of body lumens, including but not limited to coronaryand other arteries. Advantageously, the present invention facilitatesthe engagement and removal of materials in the body lumen. The inventionmay also be adapted to remove larger amounts of material in each cuttingmotion.

[0022] Apparatus according to the present invention will comprisecatheters having catheter bodies adapted for intraluminal introductionto the target body lumen. The dimensions and other physicalcharacteristics of the catheter bodies will vary significantly dependingon the body lumen which is to be accessed. In the exemplary case ofatherectomy catheters intended for intravascular introduction, thecatheter bodies will typically be very flexible and suitable forintroduction over a guidewire to a target site within the vasculature.In particular, catheters can be intended for “over-the-wire”introduction when a guidewire lumen extends fully through the catheterbody or for “rapid exchange” introduction where the guidewire lumenextends only through a distal portion of the catheter body.

[0023] Catheter bodies intended for intravascular introduction willtypically have a length in the range from 50 cm to 200 cm and an outerdiameter in the range from 1 French (0.33 mm; Fr.) to 12 Fr., usuallyfrom 3 Fr. to 9 Fr. In the case of coronary catheters, the length istypically in the range from 125 to 200 cm, the diameter is preferablybelow 8 Fr., more preferably below 7 Fr., and most preferably in therange from 2 Fr. to 7 Fr. Catheter bodies will typically be composed ofan organic polymer which is fabricated by conventional extrusiontechniques. Suitable polymers include polyvinylchloride, polyurethanes,polyesters, polytetrafluoroethylenes (PTFE), silicone rubbers, naturalrubbers, and the like. Optionally, the catheter body may be reinforcedwith braid, helical wires, axial filaments, or the like, in order toincrease rotational strength, column strength, toughness, pushability,and the like. Suitable catheter bodies may be formed by extrusion, withone or more lumens being provided when desired. The catheter diametercan be modified by heat expansion and shrinkage using conventionaltechniques. The resulting catheters will thus be suitable forintroduction to the vascular system, often the coronary arteries, byconventional techniques.

[0024] The cutting blades used in the present invention will usually beformed from a metal, but could also be formed from hard plastics,ceramics, or composites of two or more materials, which can be honed orotherwise formed into the desired cutting edge. In the exemplaryembodiments, the cutting blades are formed as coaxial tubular bladeswith the cutting edges defined in aligned apertures therein. It will beappreciated that the present invention is not limited to such preferredcutting blade assemblies, in a variety of other designs, such as the useof wiper blades, scissor blades or the like. Optionally, the cuttingedge of either or both the blades may be hardened, e.g., by chromeplating. A preferred chrome plating material is ME-92, available fromME-92 Operations, Inc., which may be applied according to manufacturer'sinstructions. Of course, other precision thin-film hard coatings such asa titanium nitride layer from BryCoat™ may be used to engineer thedesired surface properties.

[0025] Referring now to FIG. 1, a catheter 10 constructed in accordancewith the principles of the present invention comprises a catheter body12 having a proximal end 14 and a distal end 16. The catheter body 12typically includes a cutting mechanism 18 integrally formed with andconsidered part of the catheter body. The cutting mechanism 18 may ofcourse be a separate part which is attached to the distal end of thecatheter body during manufacture. The cutting mechanism 18 comprises afirst cutter 20 and a second cutter 22 that provides a mating surfaceagainst which material may be parted off. The first cutter 20 may be ascoop-shaped cutting blade that cuts material that is near the vicinityof the aperture 23. An atraumatic tip 24 is attached to the distal endof the catheter body, and a guidewire lumen 25 extends through theentire catheter body, cutting mechanism 18, and terminates in port 25 atthe distal tip of tip section 24. A proximal hub 30 is attached to theproximal end of catheter body 12 and comprises a perfusion/aspirationconnector 32, a guidewire connector 34, and a slider 36. The slider 36is attached to the proximal end of an actuator rod 37 which extends fromthe hub 30 through the lumen of catheter body 12 into the cuttingmechanism 18 where it is attached at a proximal end of the first cutter20. In this way, manual actuation of slider 36 in the direction of arrow38 moves first cutter 20 in the direction of arrow 40.

[0026] Referring now to FIGS. 2-4, the cutting motion of blade 20 willbe described in detail. In this embodiment of the cutting mechanism 18,the first cutter or cutting blade 20 is a scoop-shaped cutting blade asseen in FIG. 2. As the blade 20 rotates through its range of motion, thecutting edge 50 of the blade will draw an arc (as indicated by thedotted line 52) that extends outward from the aperture 23 for a portionof the blade's path. As seen in FIG. 3, this allows the blade 20 toengage material that has intruded into the aperture 23 or to moveoutside the diameter of the catheter to engage those materials in theoutward vicinity of the aperture 23. Some cutting may occur along thecutting edge 50 as the first blade 20 engages the material M. Theparting-off of the material is usually completed when the cutting edge50 clears, or in some cases engages, the mating surface or edge of thesecond cutter 22 as shown in FIG. 4.

[0027] A material collection surface 54 is usually located behind thecutting edge 50 on the cutting blade 20 in the direction of cutting. Thecollection surface 54, as shown in FIGS. 3 and 4, will urge material Mtowards the interior of the catheter. The collection surface 54 may beconcave or cupped surface which can more easily contain the material Mthat is to be parted off. The scoop-shaped cutting blade 20 may assumevarious shapes similar to a spoon, a bowl, a shovel blade, a claw, orthe like. The curved shape of the cutting blade 20 allows the blade tobe substantially contained within the catheter during delivery butextend outside the boundaries of the catheter body to engage materialduring cutting.

[0028] The first blade 20 may be actuated in various manners. As shownin the sequence of FIGS. 2-4, a pullwire 55 is used to rotate thecutting blade 20 about a pivot point 56. The pivot point 56 may bedefined by a pin passing through the blade 20 or by a protrusion on theblade which sits in a recess on the body portion of the cuttingmechanism. Spring mechanisms, gears, or various cable-based systems ofreduced size may also be used to rotate the cutting blade 20.

[0029] Referring now to FIGS. 5-8, catheters having cutting bladeslocated at the distal end of the catheter body will now be described.FIGS. 5 and 6 show catheter 59 having a spherical or “scoop-shaped”cutting blade 60 with a cutting edge 62 that can extend outwardly froman aperture 64 located at the distal end of the catheter. Positioningthe cutting blade 60 in this manner allows the catheter to bore throughobstructions in the body lumen. The cutting edge 62 can travel outwardtowards obstructive material to engage and then part-off the material.The distal end 66 of the catheter around the aperture 64 may be swagedto conform to the curved contours of the cutting blade. This creates anatraumatic outer surface that would advantageously allow the catheter toremove material from the center of a tubular body lumen without damagingthe wall of the tubular member. The cutting zone in this embodimentwould be spaced apart from the walls of the tubular body lumen ormember. Advantageously, such a swaged distal end would enable the deviceto bore into a stenosis within a stent and not contact the stent struts.Such a device, along with the embodiment shown in FIGS. 1-5, creates adevice having a reduced rigid length since the rotating scoop-shapedcutter 20 and 60 rely on rotational instead of translational motion. Asseen in FIG. 6, the rigid length is denoted by bracket 68. Like thedevice of FIGS. 2-4, a pullwire 70 is used to rotate the cutting blade60.

[0030] The positioning and exposure of the cutting blade on the distalend of the catheter may be varied. FIGS. 7 and 8 show that the aperture100 and the distal end 102 of the catheter may be shaped to facilitatematerial removal in a certain direction or for more aggressive materialremoval. The aperture 100 in FIGS. 7 and 8 allows for more radial motionof the cutting blade than the aperture 64 in the device of FIG. 5. Theaperture 100 may allow the device to remove larger amounts of materialwith each cutting motion when more aggressive removal is desired. Asseen in FIG. 8, the cutting blade 104 uses a pivot pin or bar 106 tomount the cutting blade to the distal end 102. The cutting blade 104works in conjunction with a second cutting edge 110 which mates with thecutting edge 112 on the cutting blade. Preferably, the cutting edges 110and 112 have teeth or penetrating point 114 which can penetrate thematerial and allow the cutter to grasp the material and draw it inwardstowards the interior of the catheter. Again, it can be seen that thecutting mechanism has a reduced rigid length 116 (FIG. 7) allowing thecatheter to navigate body lumens with tortuous configurations.

[0031] In another aspect of the present invention, the spherical orscoop-shaped cutting blades according to the present invention may bedesigned for both translational and rotational motion. Referring now toFIGS. 9 and 10, one embodiment of a catheter with such a cuttingmechanism will be described. FIG. 9 shows a cutting mechanism 140mounted on a catheter 142 via a shaft adaptor 144. The cutting mechanism140 has a distal aperture 150 that opens along the side wall of themechanism and extends to the forward facing distal end of the mechanism.A cutting blade 160 is mounted to reciprocate axially within theaperture 150. The cutting blade 160 has a stem 162 that slides within aslot 164 along the wall of the cutting mechanism 140. The stem 162places limits on the motion of the cutting blade 160 to createrotational movement of the cutting blade 160 at the distal-most andproximal-most positions. FIG. 9 shows the blade 160 at a distal-mostposition while FIG. 10 shows the cutting blade at a proximal-mostposition. When the center extension rod 166 pushes the cutting blade 160past the distal limit of the slot 164, the cutting blade rotatesforward. When the extension rod 166 pulls the cutting blade 160 past theproximal limit of slot 164, the cutting blade rotates backwards tocomplete the cutting motion. Moving the cutting blade 160 longitudinallyalong the cutting mechanism increases the amount of material that canparted off in each stroke of the cutting blade. As the blade 160 extendsoutside the aperture 150 when positioned for cutting, it may also engagematerial more easily.

[0032] Referring now to FIGS. 11-12, another catheter-mountable cuttingmechanism having a longitudinally reciprocating cutting blade will bedescribed. FIG. 11 shows a cutting mechanism 200 with a shaft adaptor202 for coupling with a catheter body. The mechanism 200 has aball-shaped cutting blade 210 mounted on a rail 212 that guides thecutting blade between a first position outside the diameter of thecutting mechanism (FIG. 11) and a second position substantially withinthe cutting mechanism (shown in phantom). By having a cutting blade 210travel on a rail and move outside the profile of the cutting mechanism200 as shown in FIG. 11, the catheter and cutting mechanism canadvantageously lie stationary while the blade travels outside themechanism to capture and part-off material. The cutting blade 210 asshown in FIG. 11 is mounted with at least one needle 220 for penetratingmaterial. The sharpened end 222 of the needle 220 is preferably locatedin front of the cutting edge 224 so that the needle can help the cuttingblade 210 engage the material. The blade 210 may be designed to have aplurality of material penetrating members.

[0033] Referring now to FIGS. 12 and 13, another cutting mechanism witha longitudinally moving cutting blade will now be described. FIG. 11shows a cutting mechanism 230 with a cutting blade 232 mounted in a ballor scoop 233 that reciprocates along cutter tracks 234 formed in ahousing 236. Like the device shown in FIG. 11, the cutting blade 232travels outside the diameter of the cutting housing 236 to engagematerial in the body lumen. As seen in FIG. 13, the cutting blade 232may be mounted with a stem 240 to cause rotation of the cutting bladewhen it is moved to the outermost position along the cutter track 234.The cutting blade 232 may be actuated by various methods such as bypullwires, or the like. For example, the cutting blade may be actuatedby either a central or off-center pullwire where the slot acts as atravel limit to cause rotation of the cutting blade at the end of theblade's travel.

[0034] Referring now to FIGS. 14-17, the cutting motion of atranslational and rotational cutting blade as shown in FIG. 9 will befurther described. The cutting blade 260 on the cutting mechanism inFIG. 14 may be mounted with an articulating or steerable catheter (shownin phantom) to position the cutting blade as desired. This allows thecutting blade 260 to be more easily positioned against material in thebody lumen and also adjust the direction of material removal. As seen inFIG. 14, the cutting blade 260 is usually delivered with the cuttingblade in a closed or retracted position. When the cutting mechanismnears the target material M, the cutting blade is moved to the openposition as seen in FIG. 15. When a steerable or articulating catheteris used, the cutting mechanism can be angled (FIG. 16) to moreaggressively remove material from the body lumen. The cutting blade 260will retract and rotate to part-off the body lumen material (FIG. 17).The cutting blade 260 may rotate about its pivot point while it is beingretracted or at the end of the retraction. Where the cutting mechanismis mounted on a nonsteerable catheter, the cutting mechanism may liesubstantially parallel against the body lumen wall, and the cuttingblade 260 will move longitudinally to scrape material from the bodylumen wall.

[0035] Referring now to FIG. 18, the present invention will furthercomprise kits including catheters 300, instructions for use 302, andpackages 304. Catheters 300 will generally be as described above, andthe instruction for use (IFU) 302 will set forth any of the methodsdescribed above. Package 304 may be any conventional medical devicepackaging, including pouches, trays, boxes, tubes, or the like. Theinstructions for use 302 will usually be printed on a separate piece ofpaper, but may also be printed in whole or in part on a portion of thepackaging 304.

[0036] While all the above is a complete description of the preferredembodiments of the inventions, various alternatives, modifications, andequivalents may be used. For example, the cutting blade may be orientedto cut along a variety of angles relative to the longitudinal axis ofthe catheter body. The cutting blade may be adapted for use with atissue or material capture device which is located in front of andsometimes spaced apart from the cutting blade. A suitable capture deviceis described further in commonly assigned, copending U.S. applicationSer. No. 09/______ (Attorney Docket No. 18489-001600US) filed on thesame day as the present application, the full disclosure of which isincorporated herein by reference. In some embodiments, the scoop-shapedblade may appear similar to a claw or a shovel. The term “scoop-shaped”as used herein refers generally to a device that has a cutting edge anda collection surface. Typically, the collection surface is a concavesurface located behind the cutting edge in the cutting direction. Insome alternative embodiments, the scoop-shaped cutting blade may haveadjacent perpendicular walls to form the collection surface. Althoughthe foregoing invention has been described in detail for purposes ofclarity of understanding, it will be obvious that certain modificationsmay be practiced within the scope of the appended claims.

What is claimed is:
 1. A catheter for removing material from a bodylumen, said catheter comprising: a catheter body having a proximal endand a distal end; and a scoop-shaped cutting blade mounted on thecatheter body, said cutting blade having a cutting edge and a materialcollection surface; wherein said cutting is configured to travel along acurved path about a pivot point of said cutting blade and wherein saidmaterial collection surface is located behind said cutting edge to urgematerial removed from said body lumen towards the catheter body.
 2. Acatheter as in claim 1 wherein said cutting edge is mounted to movealong a portion of said path in an outward direction from the catheterbody to engage said material.
 3. A catheter as in claim 1 wherein saidcutting edge of the cutting blade is mounted to move in an inwarddirection towards said catheter body after said cutting edge has engagedsaid material.
 4. A catheter as in claim 1 wherein said materialcollection surface comprises a concave surface.
 5. A catheter as inclaim 1 wherein said cutting blade comprises a sphere having an openingwherein an edge of the opening defines the cutting edge.
 6. A catheteras in claim 1 wherein said cutting blade is mounted on said catheterbody to reciprocate along a longitudinal path on said catheter body. 7.A catheter as in claim 6 wherein said cutting blade use a guide fordefining said longitudinal path, said guide selected from the groupconsisting of a slotted track, a rail, or a ramp on said catheter body.8. A catheter as in claim 6 wherein said cutting blade is mounted toreciprocate along said longitudinal path between a first positionplacing said cutting edge outside of said catheter body and a secondposition placing said cutting edge substantially within said catheterbody.
 9. A catheter as in claim 1 wherein said cutting blade is mountedon said catheter body to rotate about an axis perpendicular to alongitudinal axis of said catheter body.
 10. A catheter as in claim 1wherein said cutting blade includes a material engaging member mountedon said cutting blade to engage said material before said cutting edgecontacts said material.
 11. A catheter as in claim 1 wherein saidcutting blade includes at least one penetrating point mounted on saidcutting blade to engage said material before said cutting edge contactssaid material.
 12. A catheter as in claim 1 further comprising a secondcutter mounted on said catheter body to assist said cutting edge of thecutting blade in parting-off of material.
 13. A catheter as in claim 1further comprising an actuator within said catheter body to move thecutting blade along said curved path.
 14. A catheter as in claim 13wherein said actuator comprises a pullwire coupled to said cuttingblade.
 15. A catheter as in claim 1 wherein said catheter body comprisesa catheter wall with an opening from which said cutting blade extends toengage material.
 16. A catheter as in claim 1 wherein said catheter bodyhas a distal, forward facing opening from which said cutting bladeextends to engage material.
 17. A catheter as in claim 1 wherein thecatheter body comprises an atraumatic, tapered distal end with a forwardfacing opening at said distal end.
 18. A catheter as in claim 1 whereinsaid catheter body has a shaft adaptor at said proximal end.
 19. Acatheter as in claim 1 wherein said catheter body comprises a cuttingmechanism, said cutting blade mounted on said cutting mechanism.
 20. Anatherectomy catheter comprising: a catheter body having a proximal endand a distal end; a cutting mechanism mounted on said distal end of thecatheter body; and cutting means rotatably mounted on said cuttingmechanism for removing material from a body lumen.
 21. A catheter as inclaim 20 wherein said cutting means comprises a scoop-shaped cuttingblade having a cutting edge mounted to move along a curved path about apivot point of said cutting blade.
 22. A catheter as in claim 21 whereinsaid cutting blade includes a collection surface located behind saidcutting edge in the cutting direction.
 23. A catheter as in claim 21wherein said cutting blade is mounted to move in an outward directionfrom the catheter body for a portion of said curved path.
 24. A methodfor removing material from a body lumen, the method comprising:positioning a catheter body having a scoop-shaped cutting blade adjacentto said target material in the body lumen, said cutting blade having acutting edge and a material collection surface; and rotating saidcutting blade about a pivot point to engage and cut said target materialwhile urging the material into the catheter body with said materialcollection surface.
 25. A method as in claim 24 further comprisingreciprocating said cutting blade along a longitudinal path on saidcatheter body to remove material.
 26. A method as in claim 25 whereinsaid reciprocating of said cutting blade along said longitudinal pathoccurs while said cutting blade is being rotated.
 27. A method as inclaim 25 wherein said longitudinal moving step reciprocates the cuttingblade between a first position where the cutting edge is outside thecatheter body and a second position wherein the cutting edge is withinthe catheter body.
 28. A method as in claim 25 further comprisingpiercing said material with a penetrating member in advance of engagingthe material with said cutting edge.
 29. A method as in claim 25 whereinsaid rotating of the cutting blade brings the cutting edge adjacent to asecond cutting edge of a second cutter.
 30. A method as in claim 29wherein said second cutter is mounted on said catheter body.
 31. A kitcomprising: a catheter having a scoop-shaped cutting blade; instructionsfor use in removing material from a body lumen comprising positioningsaid catheter adjacent to said material in the body lumen, said cuttingblade having a cutting edge and a material collection surface, androtating said cutting blade about a pivot point to engage and cut saidmaterial while urging the material into the catheter body with saidmaterial collection surface; and a package adapted to contain the deviceand the instructions for use.